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Block, Jason

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Block

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Block, Jason

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Now showing 1 - 9 of 9
  • Publication

    Population Trends and Variation in Body Mass Index from 1971 to 2008 in the Framingham Heart Study Offspring Cohort

    (Public Library of Science, 2013) Block, Jason; Subramanian, Sankaran; Christakis, Nicholas A.; O'Malley, James

    Objective: We examined body mass index (BMI) across place and time to determine the pattern of BMI mean and standard deviation trajectories. Methods: We included participants in the Framingham Heart Study (FHS) Offspring Cohort over eight waves of follow-up, from 1971 to 2008. After exclusions, the final sample size was 4569 subjects with 28,625 observations. We used multi-level models to examine population means and variation at the individual and neighborhood (census tracts) levels across time with measured BMI as the outcome, controlling for individual demographics and behaviors and neighborhood poverty. Because neighborhoods accounted for limited BMI variance, we removed this level as a source of variation in final models. We examined sex-stratified models with all subjects and models stratified by sex and baseline weight classification. Results: Mean BMI increased from 24.0 kg/m2 at Wave 1 to 27.7 at Wave 8 for women and from 26.6 kg/m2 to 29.0 for men. In final models, BMI variation also increased from Waves 1 to 8, with the standard deviation increasing from 4.18 kg/m2 to 6.15 for women and 3.31 kg/m2 to 4.73 for men. BMI means increased in parallel across most baseline BMI weight classifications, except for more rapid increases through middle-age for obese women followed by declines in the last wave. BMI standard deviations also increased in parallel across baseline BMI classifications for women, with greater divergence of BMI variance for obese men compared to other weight classifications. Conclusion: Over nearly 40 years, BMI mean and variation increased in parallel across most baseline weight classifications in our sample. Individual-level characteristics, especially baseline BMI, were the primary factors in rising BMI. These findings have important implications not only for understanding the sources of the obesity epidemic in the United States but also for the targeting of interventions to address the epidemic.

  • Publication

    Consumers’ estimation of calorie content at fast food restaurants: cross sectional observational study

    (BMJ Publishing Group Ltd., 2013) Block, Jason; Condon, Suzanne K; Kleinman, Kenneth Paul; Mullen, Jewel; Linakis, Stephanie; Rifas-Shiman, Sheryl; Gillman, Matthew

    Objective: To investigate estimation of calorie (energy) content of meals from fast food restaurants in adults, adolescents, and school age children. Design: Cross sectional study of repeated visits to fast food restaurant chains. Setting: 89 fast food restaurants in four cities in New England, United States: McDonald’s, Burger King, Subway, Wendy’s, KFC, Dunkin’ Donuts. Participants: 1877 adults and 330 school age children visiting restaurants at dinnertime (evening meal) in 2010 and 2011; 1178 adolescents visiting restaurants after school or at lunchtime in 2010 and 2011. Main outcome measure Estimated calorie content of purchased meals. Results: Among adults, adolescents, and school age children, the mean actual calorie content of meals was 836 calories (SD 465), 756 calories (SD 455), and 733 calories (SD 359), respectively. A calorie is equivalent to 4.18 kJ. Compared with the actual figures, participants underestimated calorie content by means of 175 calories (95% confidence interval 145 to 205), 259 calories (227 to 291), and 175 calories (108 to 242), respectively. In multivariable linear regression models, underestimation of calorie content increased substantially as the actual meal calorie content increased. Adults and adolescents eating at Subway estimated 20% and 25% lower calorie content than McDonald’s diners (relative change 0.80, 95% confidence interval 0.66 to 0.96; 0.75, 0.57 to 0.99). Conclusions: People eating at fast food restaurants underestimate the calorie content of meals, especially large meals. Education of consumers through calorie menu labeling and other outreach efforts might reduce the large degree of underestimation.

  • Publication

    Do residents of food deserts express different food buying preferences compared to residents of food oases? A mixed-methods analysis

    (BioMed Central, 2012) Block, Jason; Kawachi, Ichiro

    Background: Many people lack access to food stores that provide healthful food. Neighborhoods with poor supermarket access have been characterized as “food deserts” (as contrast with “food oases”). This study explored factors influencing food buying practices among residents of food deserts versus food oases in the city of Boston, USA. Methods: We used the mixed-methods approach of concept mapping, which allows participants to identify, list, and organize their perceptions according to importance. Resulting maps visually illustrate priority areas. Results: Sixty-seven low-income adults completed the concept mapping process that identified 163 unique statements (e.g. relating to affordability, taste, and convenience) that influence food buying practices. Multivariate statistical techniques grouped the 163 statements into 8 clusters or concepts. Results showed that average cluster ratings and rankings were similar between residents of food deserts and food oases. Conclusions: The implication of this study pertains to the importance of community resources and emergency food assistance programs that have served to minimize the burden associated with hunger and poor food access among low-income, urban populations.

  • Publication

    Time series analyses of the effect of FDA communications on use of prescription weight loss medications

    (Wiley-Blackwell, 2014) Block, Jason; Choudhry, Niteesh; Carpenter, Daniel; Fischer, Michael; Brennan, Troyen; Tong, A. Y.; Matlin, O. S.; Shrank, William

    OBJECTIVE: To determine the impact of FDA safety communications regarding the weight loss medications sibutramine and orlistat. METHODS: The 2008 to 2011 pharmacy claims data from CVS Caremark were used to determine the effect of the relevant FDA warnings on (1) use of sibutramine and orlistat, (2) their rates of discontinuation, and (3) substitution to an alternate weight loss medication in the 3-month period following discontinuation. RESULTS: The use of sibutramine, orlistat, or phentermine declined from 45 users per 100,000 Caremark enrollees in May 2008 to 24 users per 100,000 enrollees in December 2010. In the time series analyses of overall use of medications, a very small decline in the trend of use of sibutramine after the FDA communication (0.000002% per month decline after the communication; P < 0.001) was found. However, rates of discontinuation of sibutramine and orlistat were similar before and after relevant FDA communications (all P values >0.1 for both level and trend changes post-warning). Patients discontinuing sibutramine post-communication increased use of phentermine at a rate of 0.004% per month after discontinuation (P = 0.01). CONCLUSION: From 2008 to 2010, use of prescription weight loss medications was low and declined over time. FDA communications regarding the safety of these medications had limited effect on use.

  • Publication

    Quantifying the foodscape: A systematic review and meta-analysis of the validity of commercially available business data

    (Public Library of Science, 2017) Lebel, Alexandre; Daepp, Madeleine I. G.; Block, Jason; Walker, Renée; Lalonde, Benoît; Kestens, Yan; Subramanian, S. V.

    This paper reviews studies of the validity of commercially available business (CAB) data on food establishments (“the foodscape”), offering a meta-analysis of characteristics associated with CAB quality and a case study evaluating the performance of commonly-used validity indicators describing the foodscape. Existing validation studies report a broad range in CAB data quality, although most studies conclude that CAB quality is “moderate” to “substantial”. We conclude that current studies may underestimate the quality of CAB data. We recommend that future validation studies use density-adjusted and exposure measures to offer a more meaningful characterization of the relationship of data error with spatial exposure.

  • Publication

    Moving Beyond “Food Deserts”: Reorienting United States Policies to Reduce Disparities in Diet Quality

    (Public Library of Science, 2015) Block, Jason; Subramanian, S. V.

    Jason Block and S. V. Subramanian explore avenues for improving the health of Americans through reducing dietary inequalities and look at whether concern over "food deserts" has been taken too far.

  • Publication

    Protocol for an Experimental Investigation of the Roles of Oxytocin and Social Support in Neuroendocrine, Cardiovascular, and Subjective Responses to Stress across Age and Gender

    (BioMed Central, 2009) Kubzansky, Laura; Mendes, Wendy B; Appleton, Allison; Block, Jason; Adler, Gail

    Background: Substantial empirical evidence has demonstrated that individuals who are socially isolated or have few positive social connections seem to age at a faster rate and have more chronic diseases. Oxytocin is a neurohypophyseal hormone hypothesized to coordinate both the causes and effects of positive social interactions, and may be involved in positive physiological adaptations such as buffering the deleterious effects of stress and promoting resilience. The proposed research will examine whether and how oxytocin influences responses to stress in humans and will consider effects in relation to those of social support. Methods/Design: Experimental research will be used to determine whether exogenously administered oxytocin (intranasal) influences psychological and physiological outcomes under conditions of stress across gender and age in adulthood. Hypotheses to be tested are: 1) Oxytocin ameliorates the deleterious neuroendocrine, cardiovascular, and subjective effects of stress; 2) Oxytocin and social support have similar and additive stress-buffering effects; 3) Oxytocin effects are stronger in women versus men; and 4) Oxytocin effects are similar across a range of adult ages. Hypotheses will be tested with a placebo-controlled, double-blind study using a sample of healthy men and women recruited from the community. Participants are randomly assigned to receive either oxytocin or placebo. They undergo a social stress manipulation with and without social support (randomly assigned), and outcome measures are obtained at multiple times during the procedure. Discussion: Understanding the determinants of healthy aging is a major public health priority and identifying effective measures to prevent or delay the onset of chronic diseases is an important goal. Experimental research on oxytocin, social relationships, and health in adulthood will contribute to the scientific knowledge base for maximizing active life and health expectancy. At conclusion of the study we will have solid evidence concerning the effects of oxytocin on stress response and whether it has similar effects across age and gender groups. A neurobiological understanding of resilience can inform efforts for both prevention and intervention of diseases or problems common in later life. Trial registration Clinical trial identification number is NCT01011465.

  • Publication

    Changes in the food environment over time: examining 40 years of data in the Framingham Heart Study

    (BioMed Central, 2017) James, Peter; Seward, Michael; James O’Malley, A.; Subramanian, SV; Block, Jason

    Background: Research has explored associations between diet, body weight, and the food environment; however, few studies have examined historical trends in food environments. Methods: In the Framingham Heart Study Offspring (N = 3321) and Omni (N = 447) cohorts, we created food environment metrics in four Massachusetts towns utilizing geocoded residential, workplace, and food establishment addresses from 1971 to 2008. We created multilevel models adjusted for age, sex, education, and census tract poverty to examine trends in home, workplace, and commuting food environments. Results: Proximity to and density of supermarkets, fast-food, full service restaurants, convenience stores, and bakeries increased over time for residential, workplace, and commuting environments; exposure to grocery stores decreased. The greatest increase in access was for supermarkets, with residential distance to the closest supermarket 1406 m closer (95% CI 1303 m, 1508 m) by 2005–2008 than in 1971–1975. Although poorer census tracts had higher access to fast-food restaurants consistently across follow-up, this disparity dissipated over time, due to larger increases in proximity to fast-food in wealthier neighborhoods. Conclusions: Access to most food establishment types increased over time, with similar trends across home, workplace, and commuter environments. Electronic supplementary material The online version of this article (doi:10.1186/s12966-017-0537-4) contains supplementary material, which is available to authorized users.

  • Publication

    “If It Tastes Good, I'm Drinking It”: Qualitative Study of Beverage Consumption Among College Students

    (Elsevier BV, 2013) Block, Jason; Gillman, Matthew; Linakis, Stephanie K.; Goldman, Roberta

    Purpose

    This study examined how college students choose beverages and whether behavioral interventions might reduce their heavy consumption of sugar-sweetened beverages.

    Methods

    From April to June 2010, 90 students participated in 12 focus groups at 6 colleges in Massachusetts and Louisiana. The study team undertook a group content analysis of the verbatim focus group transcripts using the immersion-crystallization method.

    Results

    The mean age of participants was 19 years. 50% were white, and 47% were black. Several themes emerged in focus groups: taste is paramount; price is important but secondary; health and nutritional content of beverages are of limited interest; juice has a “health halo”; and water is consumed primarily for hydration. Students were often highly fixated on favorite sugar-sweetened beverages. Price was uniquely important for good-tasting beverages costing less than one dollar. Some students reported calorie content as important for food choices, but most had no awareness of beverage calorie content. Students’ negative perceptions of sugar-sweetened beverages focused largely on the “dangers” of sugar and chemicals in sodas. They expressed particular concern about soda’s corrosive chemical properties or diet soda causing cancer. The health halo for juice persisted even with some recognition of high sugar content. Students thought shocking educational messages would be necessary to get them to reduce consumption of sugar-sweetened beverages.

    Conclusions

    Among college students, taste and price were the most important factors in choosing beverages. Interventions using shocking visual images or providing low-cost or free water may conquer taste and brand preference to reduce sugar-sweetened beverage intake.